Sled that is 1/2 a turn out on the air screw seems to cut out right off idle at low RPM, sled that is 1 turn out on the air screw seems to sing right along through the entire RPM range. Sled that is 1/2 a turn out does just fine at higher RPM ranges though.

My question is, can the air screw adjustment cause this cutting out condition? Or is the cutting out probably related more to an ignition issue?

I'm honestly not familiar with the 2 stroke carbs, I've messed with plenty of 4-stroke dirt bike carbs, but I'm not sure what the air screw adjustment does on the 2 stroke carbs.

Just outta curiosity, what are the "new" factory recommended settings for this sled? I've been screwing with these things for 2 days and I can't tune this low end bog out of them right now.

I have them set up with a 0.9 or a 0.6 air screw depending on the sled I've tried the fuel screw from 1/2 a turn to 2 1/2 turns out, 50 pilots, 55 pilots, you name it and it just stumbles like crazy off idle ...

Can bad fuel cause that as well? Runs great from about 1/3 to full throttle.

My 07 600 rmk had a stumble last year, started in bighorns, pulled all the jets, mains, pilots, pilot airjets fuel lines, blew out carbs and sprayed with carb cleaner. That worked!!! Agree with Marv try 40 or 45 pilots, maybe .6 or.7 paj, good luck PS it doesnt have an air screw, the white knob is the fuel screw, dont go less than 1/2 in, out more fuel, good luck Marv whats a wowzer???